Tankers and vessels contain highly hazardous liquids and gases that are processed through plant pipelines. If you continue browsing the site, you agree to the use of cookies on this website. Corrosion under insulation and fireproofing 1 scope this recommended practice rp covers the design, maintenance, inspection, and mitigation practices to address external corrosion under insulation cui and corrosion under fireproofing cuf. Analysis of a corrosion under insulation failure in a carbon steel refinery hydrocarbon line article pdf available in case studies in engineering failure analysis 14. This remains the case today as engineers combine several nde. Corrosion under insulation european federation of corrosion. The water entering into the insulation reaches a point of dry out at the equipment wall or the hot pipe. Here a leak can cause safety and environmental concerns, and international headlines as well. Advisory bulletin warns about corrosion under insulation.
Corrosion under insulation cui has long been an underestimated problem. Corrosion under insulation cui refers to the external corrosion of piping and vessels fabricated from carbon manganese, low alloy and austenitic stainless steel that occurs underneath externally cladjacketed insulation due to the penetration of water. Because the corrosion is hidden under the insulation, cui tends to. Pdf available prediction methods for corrosion under insulation. The type and rate of corrosion under insulation will vary. Corrosion under insulation cui cui is a particularly severe form of localized corrosion that has been plaguing chemical process industries since the energy crisis of the 1970s forced plant designers to include much more insulation in their designs intruding water is the key problem in cui. The following article is a part of the national board technical series. By its very nature cui tends to remain undetected until the insulation and claddingjacketing is removed to allow inspection or when leaks occur. The key issue in this case was the incorrect specification of ioz silicate for use in this temperature range under insulation. Sustainability free fulltext combined experimental and field.
Corrosion under insulation cui is a damage mechanism that affects all industrial facilities. A guide to galvanized steel free pdf downloads provided by. Corrosion under insulation cui guidelines 1st edition. All information about the articles is based on the original dates of publication of these materials in jpcl. Tmi coatings removed existing sprayed in place foam insulation, sandblasted, and painted three 3 170 diameter ground storage tanks. Corrosion under insulation loop steam drum present by. Corrosion under insulation cui refers to the external corrosion of piping and vessels that occurs underneath externally cladjacketed insulation as a result of the penetration of water. The european federation of corrosion efc working parties wp and wp15 have worked to provide guidelines on managing cui together with a number of major european refining, petrochemical and offshore companies including bp, chevrontexaco, conocophillips, eni, exxonmobil, ifp, mol, scanraff, statoil, shell, total and borealis. Corrosion under insulation cui alliance carry out corrosion under insulation cui surveys across the uk and is perhaps one of the most significant integrity threats that the oil and gas industry faces today. Corrosion under insulation inspection and prevention.
Acuren is thinking outside the box, pioneering alternative strategies for tackling this. The transferred electrons will combine with water molecule and oxygen. Corrosionunderinsulation cui, if left to its own devices, can and does cause serious and sometimes catastrophic consequences with piping systems and related components and equipment. Corrosion under insulation cui is one of the increasing industrial problems, especially in chemical plants that have been running for an extended time. This is an exciting area developed in order to assist with the location of likely areas of cui. Patiphon suksawat slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. During removal of the old insulation and leadbased paint, an aging wood framed base on the concrete foundation was discovered. Failure of inservice equipment can be catastrophic and extremely costly. Page 1 corrosion under insulation cui creates a pervasive and versatile.
Corrosion under insulation cui and how to prevent it. Cui is difficult to detect until the insulation is removed for inspection or when corrosion damage leads to the failure or leaks. Pdf analysis of a corrosion under insulation failure in. Corrosion under insulation cui is the corrosion of piping and vessels that occurs beneath insulation as a result of water penetration. Corrosion under insulation cui is a special form of external corrosion, it refers the corrosion of piping and vessels that occurs beneath insulation following water ingression. This article was originally published in the january 1988 national board bulletin. Bn allows us to combine expert opinions, data, and analytical models in a single. Corrosion under insulation can be simulated and the efficiency of the treatments applied can be investigated successfully in a laboratory cell.
Stp880 corrosion of metals under thermal insulation. New developments in automated inspection for corrosion under insulation john rudlin, twi limited, cambridge, uk abstract detection of corrosion under insulation cui has been a major problem for the oil, gas and chemical industries for many years. Api rp 583 covers design, maintenance, and inspection practices for processing equipment due to external corrosion under insulation cui or fireproofing. The purposes of our study are to identify optimum locations for inspection of insulated equipment and to identify improvements in new equipment design and insulation, as well as maintenance of existing systems. Corrosion under insulation cui is one of the costliest problems facing the petrochemical industry today. Corrosion under insulation cui is external corrosion due to the collection of water in annulus spaces, between the insulation and the metal surface. Corrosion under insulation cui is a major safety threat to chemical processes with pipes and pressure vessels for moving and storing fluids where anions and cations are transported via water to pipe surfaces to corrode away pipe surfaces. Moisture, leaking substances often corrosive, flammable or toxic and weathering conditions can lead to deterioration of insulation and corrosion of underlying vessels or pipes.
Corrosion under insulation cui on industrial piping is. Corrosion under insulation cui is a problem in the industrial sector, including refining, petrochemical, power, industrial, onshore and offshore industries and it is a real threat to the on stream reliability of many of todays plants. For the love of physics walter lewin may 16, 2011 duration. Pdf corrosion under insulation cui is an increasingly important issue for the piping in industries especially. New developments in automated inspection for corrosion. According to one specifier from a major oil company, cui problems account for more unexpected downtime than all other possible causes combined. Corrosion under insulation cui resource library johns manville. Emphasis is placed on equipment design features, operating temperature, and weather barrier deficiencies to guide inspection. Corrosion under insulation cui is one of the most wellknown phenomena in the process industries, and yet it still makes up an inordinately large percentage of global maintenance expenditures. Factors affecting corrosion of carbon steel under thermal.
Corrosion under insulation cui is a major common problem shared by all of the refining, power. Designing and installing your insulation system to address corrosion under. The 7 inspection methods you must know about published on april 14, 2016 april 14, 2016 745 likes 74 comments. Cui is a subject that is wellresearched and understood.
Corrosion under insulation purdue university college of. Corrosion under insulation, and 4 examples from the u. Dive into the details of how to combine jacketing and insulation to create a robust. According to many corrosion engineers, problems such as major equipment stoppages unexpected maintenance costs stemming from cui result in more unplanned downtime than all other causes. Such products are often heated for more efficient transport, thus the pipe is wrapped with foam insulation over the coating, and then further covered with a tape wrap over the insulation. Corrosion under insulation cui is perhaps one of the most significant. Corrosion under insulation is caused by the ingress of water into the insulation, which traps the water like a sponge in contact with the metal surface. All around the world, oil refineries face enormous problems with severe corro sion as well as high maintenance costs to keep corrosion under control.
The water can come from rain water, leakage, deluge system water, wash water, or sweating from temperature cycling or low temperature operation such as refrigeration units. Concern about corrosion under insulation is shown by major oil companies who operate above the arctic circle. An indepth analysis, which appeared in the november 2006 issue of insulation outlook,1 described the mechanism of corrosion under insulation cui for carbon steel and stainless steel, as well as prevention tools and techniques available to minimize cuis effects. Corrosion under insulation cui guidelines 2nd edition. Another zone next to the dry out has pores of insulation, but they are filled with saturated salt solution. Corrosion under insulation and fireproofing draft committee.
A recent phmsa advisory bulletin warns the pipeline industry about corrosion under insulation cui, which is frequently used on pipe transporting heavy crude oil. Corrosion under insulation or composite wrappings has become a major concern in aging. Save energy control process temperatures protect workers from high temperatures nace standard rp0198981 is a good source of information, but electrolytes will eventually find their way. Conclusions based on the testing program described herein, the following conclusions were made. Corrosionunderinsulation cui refers to the external corrosion of piping and vessels that occurs underneath externally cladjacketed insulation as a result of the penetration of water. Current industry practices for detection and mitigation are inefficient and expensive.
Corrosion under insulation can be extremely harmful within the oil, gas, and petrochemical industries. Corrosion rates of carbon steel can be significant if operating at high temperatures and subject to temperature cycling, particularly when thermally insulated approximately 35% of incidences of corrosion failures, or near failures were caused as a result of corrosion under insulation this statement follows a 2 year survey of. The 4 best nondestructive inspection methods for corrosion. Efc guideline n 55 corrosion under insulation new edition nov. Cui is insidious, difficult to detect and can be expensive to mitigate. Corrosion under insulation cui cui has been recognized as a problem in many industries insulation is a necessary component of the system and is designed to. Corrosionpedia what is corrosion under insulation cui. When an ammonia refrigeration system in their plant. Corrosion under insulation cui corrosion under insulation is one of the costliest problems attacking industry today. The difficulties and expense of looking for and preventing the very common but elusive problem of corrosion under insulation cui is widely known and well documented cui is hard to find because its hidden under the insulation and there are substantial costs and logistical issues involved in removing the coverings, inspecting the piping and then reinstating the coverings.
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